This invention relates to the accurate storage and retrieval of items from bins in an automated manufacturing system.
Automated parts storage and retrieval is a part of integrated automated manufacturing systems now being considered and constructed for virtually all areas of manufacturing. Such devices can be used either for temporary or long term storage of unmachined or machined parts, or for transport of parts from one manufacturing station to another. Typically, in conventional systems parts bins are accessed manually by a human operator who scans a series of bins for the desired part. In other operations, parts are physically carried from one machining center to another by parts bins on carousels or conveyors.
These activites have been gradually changing as automation increases in the factory. In instances where hundreds or thousands of parts must be accessed, complex electro-mechanical systems have been devised which automatically store and retrive parts. These systems can be procured commercially at great cost and generally require large storage areas and large bins. The need for quick and accurate accessing of parts storage bins without having to resort to overly complex and expensive devices is as yet unsatisfied.
The inherent positioning inaccuracies found in conventional drive mechanisms for conveyors and carousels generally stem from a number of factors, including chain or drive link stretching, gear backlash, inaccurate fabrication and loose assembly tolerances. These mechanical inaccuracies limit conventional devices in a number of ways. These limitations include large minimum bin spacing, large minimum bin size and low maximum speed. Exceeding these limtations by decreasing bin spacing or increasing speed results in erroneous accessing of incorrect bins.
It is an object of the present invention to provide a mechanism for accurately accessing a large number of closely spaced bins for the purposes of part removal or storage.
It is a further object of this invention to provide a mechanism that will accomplish the above object and yet be relatively simple to construct and inexpensive to manufacture.
Finally it is a further object of this invention to provide an automated, computer controlled parts storage and retrieval device that can be easily integrated into a larger computer controlled environment such as found in automated factories.